Incandescent eleoteic lamps



2 Sheets-Sheet 1* (No Medel.)

. OLA. MOSES. METHOD OP'MANUFAGTURING INCANDESUBNT ELECTRIC LAMPS.

Patented Alig. 11, 1885.

INVENTOR WITNESSES W4 6L Otto .fl Moses,

By his Attorneys N. FEYERS. Phuwmhngnphir. Vlnnmgiun, D- C.

2 Sheets-Sheet 2.4 I

(No Model.)

0. A. MOSES. METHOD 015 MANUPAOTURING INGANDESGENT ELECTRIC LAMPS.

No. 324,334. Patented Aug. 11,1885.

INVENTOR Otto .fl. Moses, By hi6 Attorneys Mgwgj WITNESSES.

N. PEIERS. Phulwljlhogriplw Wfllhington, D4 C.

UNITED STATES PATENT ()FFICE.

OTTO A. MOSES, OF NEW YORK, N. Y.

METHOD OF MANUFACTURING INCANDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 324,334, dated August11, 1885.

Application filed October 29, 1883.

To all whom it may concern:

Be it known that I, OTTO A. MosEs, a citizen of the United States, and aresident of the city, county, and State of New York, have invented acertain,new and useful Improvement in the Method or Process ofManufacturing Incandescent Electric Lamps, of which the following is aspecification.

My invention relates to that class of electric lamps in which aconducting strip, wire, or filament of carbon, hydrocarbon, or othersuitable refractory substance is mounted by means of supportingconductors within a transparent air-tight globe or chamber from whichthe air is exhausted, and which may or may not be filled with anon-oxidizing gas or vapor. The said conducting strip, wire, or filamentis rendered incandescent when traversed by an electric current, andthereby caused to emit a brilliant light.

My present invention relates, particularly, to improvements in themethod or process of sealing the chamber itself after the air has beenexhausted therefrom.

My improvements are illustrated in the accompanying drawings, theseveral figures of which represent lamps and parts of lamps as theyappear during consecutive stages in the process of manufacture, ashereinafter more fully set forth.

In making my improved incandescentlamp, I first take a cylindrical glasstube, A, Fig. 1, having an external diameter of one inch and a thicknessof one-sixteenth of an inch, which has a bulb, B, formed upon it by theordinary and well-known process of glass-blowing, al-' though a bulbblown directly on the punty from the metal in the glass-makers cruciblemay be substituted therefor. This tube is placed in a lathe and cut offby the aid of a diamond or otherwise at a point about onefourth of aninch from the shoulder, as shown at 00 w in Fig. 1. The cut edges of theshort neck thus remaining upon the bulb are next rounded by partialfusion in an oxidizing blow-pipe flame, care being taken that theinternal diameter of the tube is not diminished during the operation.After the completion of this step in the process the bulb presents theappearance shown in Fig. 2. Another piece of glass tube is next taken,the original diameter of which, as shown atv O in vex or hemisphericalform.

(No model.)

Fig. 3, is such as to enable it to fit closely within the tubular neckof the bulb B. This piece of tube has originally a length of about twoand one-halfinches, as indicated by the dotted lines. Its extremitiesare then softened in the flame and drawn out in a conical form, as shownat c c in Fig. 3, leaving the middle portion, C, of its originaldiameter and thickness and about three-fourths of an inch in length. Themiddle portion, 0, of the tube is next closed at its upper end and contracted at its lower end, as shown in Fig. 4, both ends being madeapproximately of a con- The diminished lower prolongation c is next cutoff close to the shoulder, so as to form a short neck, 0, having anopening within it. Apiece of stout tube, D, three-sixteenths of an inchin diameter and of convenient length for handling, is

enlarged at its upper end, so that it will fit over the neck 0, as shownin Fig. 4, after which the two parts are fused together, or, as it istechnically termed, soldered, in the blow-pipe flame and drawn down intothe form shown in Fig. 5, leaving a narrow opening at d. A smallaperture, 0", is then made in the closed top of the tube 0, throughwhich a platinum pin or stopper, e, bent into a hook at its upper end,is dropped into the orifice d of the tube, which it closely fits, asshown in Fig. 6, although not accurately enough to be air-tight. Thispin may then be slightly bent by softening and manipulating thesurrounding glass, so that it will not be liable to drop out during theinversion of the bulb rendered necessary in subsequent steps in themanufacture. The tube 0 is inserted into the neck I) of the bulb B, asshown in Fig. 7, which it fits very closely, forming asliding ortelescopic joint. This joint is then surrounded externally by a strongoxidizing blow pipefiame playing upon every side of it, by the action ofwhich the neck of the bulb and the tube Gare fused into, a solid mass.The bulb B and tube 0, having thus been sealed together and brought tothe condition represented in Fig. 7 are attached to a mercury or othersuitable vacuum pump by means of the tubular stem D, and the air isexhausted from the interior of the bulb and tube, as perfect a vacuum aspossible being obtained. The contracted neck d is then softened bysurrounding it by a blowpipe flame, and is elongated and at the sametime otherwise compressed around the platinum stopperE, this operationbeing materially assisted by the external atmospheric pressure. The tubeis then cut off at the point shown by the dotted line 3 y, and the lowerend of the neck D is plunged into a vessel of molten lead or otherfusible metal, by which the glass is softened and annealed, while at thesame time the atmospheric pressure forces the lead into any minuteinterstices which may exist between the platinum stopper E and thesurrounding glass. A small button of lead alloyed with platinum willadhere to the lower end of the stopper at the completion of thisoperation, as shown in Fig. 8. Finally, the sealing of the chamber iscompleted by the alternate application of an oxidizing and a reducingblowpipe flame to the lower part of the stem, by I which the lead orother metal is chemically united or alloyed both with the glass and withthe platinum stopper, forming, in case lead is used, a layer of silicateof lead between the lead and the glass, which passes gradually intoglass on one side and lead on the other, and also alloying the platinumand lead at their surfaces of contact. In this manner the openingthrough which the air has been exhausted is sealed in the most effectualand permanent manner.

The lamp is now in readiness to be mounted in its supports and connectedwith the electric conducting-wires, which are united bysoldering orotherwise to the conductors which project from the walls of thevacuum-chamber. V

I stopperinto the neck of said chamber, softening and compressing theglass of the neck around said stopper, and plunging the neck with thestopper into molten lead or otherlike fusible metal, whereby the glassis softened and annealed and the molten metal alloyed with the stopperand cheniically united with the glass.

In testimony whereof I have hereunto subscribed my name this 16th day ofOctober, A. D. 1883.

OTTO A. MOSES.

\Vi tn esses:

CARRIE E. DAVIDSON, Ormumcs A. TERRY.

